Research On The Influence Of Elevated Curing Temperature On The Strength And Durability Of High-strength Concrete

With the rapid development of construction industry in China, prestressed PHC pipe piles are widely used for bridges, housing and other civil structures. In the manufacturing of PHC pipe pile, using steam + autoclave curing can speed up the hydration of cementitious materials and improve the concrete’s early mechanic properties. In some cases, the service environment of prestressed concrete pile becomes worse due to the existence of harmful substance. Recent years’ research found that concrete’s durability of pile body declined to different extents, the reason need to be researched. In this paper, we studied the effect of influence factors and non-autoclaved curing temperature on the mechanic performance and permeability of high-strength concrete.Before the analysis of the durability of C80 high-strength concrete used in prestressed centrifugal pile, the goals in the process of production were put forward by adjusting the raw materials and process parameters. The effects of water to cement ratio, sand ratio, steam curing system and others on the mechanical property of C80 concrete used in pile were studied. On this basis, we summarized the influence law and application requirement in the process of production by choosing suitable raw materials and mix proportion. Then finally provided a best mixture ratio and steam curing system for C80 high-strength concrete used in the manufacturing of prestressed centrifugal pile.Using XRD, SEM and thermal analysis and other modern analytical techniques to describe and analyze the hydration products, microstructure, phase composition, thermal stability under the different steam curing system of C80 high-strength concrete used in prestressed centrifugal Pile. By this may, the hydration mechanism of cementitious material and the durability of concrete ca be systematically studied. At last, an appropriate mix proportion and steam curing region of C80 high-strength concrete is obtained after considering mechanic properties and durability.